Vehicle seat tilt adjustment is an important feature to automotive vehicle purchasers. A vehicle seat can be made more comfortable for drivers and passengers by providing a convenient "user friendly" tilt adjustment. On long drives, it is helpful to occasionally adjust the degree of seat back inclination for driver comfort. Passengers may also wish to adjust the seat back periodically to a more comfortable position.
Vehicle seat tilt adjustment devices can generally be categorized into two groups, constantly engaged adjustment mechanisms and disengagable adjustment mechanisms. Constantly engaged mechanisms such as those disclosed in U.S. Pat. No. 4,358,155 and 4,402,547 are usually more difficult to use. A knob is turned manually to adjust the seat back position.
Many drivers prefer a disengagable tilt adjustment wherein a lever is pushed to release the seat back tilt lock while the user moves his back to the new position. An example of a disengagable adjustment mechanism is disclosed in U.S. Pat. No. 3,602,547. During tilt adjustment, the seat back is disengaged and is free to move forward or backward within a limited range. With disengagable tilt adjustment mechanisms, the seat is typically urged to its full up-right position by a spring biasing means. Such devices are generally considered safe and effective tilt adjustment mechanisms.
These and other problems are addressed by the invention as summarized below.